Method for wireless directive signaling



Patented Feb. 8, 1927.

UlTED STATES- REGINALD A. FESSENDEN, OF CHESTNUT HILL, MASSACHUSETTS.

METHOD FOR WIRELESS DIRECTIVE SIGNALING.

No Drawing.

My invention relates to methods of directive signaling by wireless, and has for its object greater reliability of operation and the elimination of errors and disturbances.

During the years 1899-1918, applicant made many hundreds of experiments on methods of wireless signaling on wave lengths varying from a few centimeters to more than six thousand (6000) meters. An

account of these experiments and the results obtained was published by applicant, and will be found in the Proceedings of the American Institute of Electrical Engineers,

November, 1899 and July, 1908, The Electrical Review, London, May 11th and 18th, 1906 and February 15th, February 22nd, and March 1st, 1907; and The Electrician, London, February 15th and 22nd, 1907, and December 19th, 1919.

These articles describe, with illustrating curves, certain discoveries made by applicant as the result of these experiments, amongst them the discovery that if the pitch, i. e., frequency of the electric Waves, was 25 diminished so as to be less than seventy thousand (70,000) per second, a (so to speak) transparent band of wave lengths was reached, and that by using this low pitch,

i. e., long wave length band, reliability of transmission across the Atlantic was, for

the first time, made practicable. Applicants invention was immediately adopted, and since that time, i. e., 1907 up to the time of the publication of applicants short wave length discovery, all long distance transmission has been accomplished by the use of this long wavelow pitch band of electric waves.

Shortly after 1914, in connection with 40 problems relating to aeroplane and submarine signaling where high masts, and therefore. long wave lengths could not be used, applicant investigated his records on the lower wave lengths, i. e., between three hundred (300) meters and a few centimeters. As wave lengths of a few centimeters was considerably worse than that of. wave lengths of three hundred (300) meters, he wished to know at exactly what point the diminution of efficiency began to occur.

To his great surprise, he discovered what had hitherto beenunsuspected by himself, and apparently by anyone else, i. e., that there was a very short so to speak, trans- 5 parent band of wave length lying between Application filed January 28 1922. Serial No. 532,489.

fifty (50) meter wave length and one (1) meter Wave length. and that this band, as he found on calculating out his experimental data, was even more transparent than the long wave length band.

Applicant had, in the course of his experiments, and so, no doubt, had others, used wave lengths lying in this band, of the order of five (5) meters, but had never at the time, made the discovery, having. attributed the increased efficiency to accidental variations such as are common in wireless signaling, and it was not until the mass of results collected between 1899 and 1918 were tabulated and compared that applicant made the discovery.

The results could not be published at the time, as early in 1915, applicant received orders from the United States Nav and War Departments, to the effect that lnventions having military uses should not be communicated by applicant to anyone except to certain designated oflicials, and the orders were that such secrecy must be maintained until the instructions were cancelled by competent authority, which cancellation did not occur until several years after the close of the war (and copies of the secrecy orders and release orders are in the archives of the Patent Office, in the file of United States patent application, Serial No. 531,166).

The reason why this particular band is transparent is not known definitely by ap-v plicant, and, so far no explanation has been given which has been accepted by scientists generally. There are no doubt a number of reasons, but whatever they may be, it is now certain, from the many recorded results of investigations made since applicant first disclosed the fact, that applicants results are correct, and that there is a band of wave lengths which is abnormally favorable to transmission and which is of the order of five (5) meters, i. e., of a pitch, i. e., frequency, lyingbetween sixty million (60,000,000) and three hundred million (300,000,000).

What I claim is:

1. The method of obtaining increased transmission efficiency in directional wireless signalin which comprises transmitting the signals by electric waves shorter than fifty meters wave length and longer than one meter wave length, such waves having a relatively high transmission characteristic whereby said signals are transmitted with much less disturbance by injurious atmospheric effects.

2. The method of obtaining increased transmission efiiciency in directional wireless signaling which comprises transmitting the signals by means of electric waves, of a band of wave lengths characterized by a 10 high transmission efliciency, said band of wave lengths lying between fifty meters and one meter.

3. The method of obtaining increased transmission eflic ency iii directional wireless s gnaling, which comprises transmitting the signals on those wave lengths between litty meters and one meter which eifect a high transmission efficiency.

REGINALD A. FESSEN DEN. 

